#6236 made Escape put back the colour the gesture started from. In the
reference application Escape while the right button is held closes the
HUD and keeps the colour picked so far; moving the pointer afterwards
changes nothing (measured: picked 0,40,96 from 40,90,160; after Esc and
a further move it stayed 0,40,96, also after the release).
Escape now ends the gesture like the button release does. The pick is
still one coalesced history step, so Undo takes it back.
Test: Escape closes the HUD with the picked colour kept, a later move
picks nothing, and releasing the button afterwards opens nothing.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
